Condenser-discharge electric system



Patented June so, 1944 umrso s'm'rss PATENT OFFICE 2,351,603 com arison-Discusses smc'rmo ass-rm Harold Eugene Edger-ton. Belmont, Mass. Application December 6, 1941, Serial No. 421,931 as onion. (Cl. sis-241 The present invention relates to electric systems, and more particularly to condenser-char ing-and-dischargihl systems.

in common use for dash-prosimilar purposes comprises a condenser charged from a source oi direct-current energy and the charge of which is thereupon dissipated in a discharge circuit comprising a gaseous-discharge device, like a dash-lamp. The resultin flash may, ior example, be used in flash-photography.

It is frequently desired, however, in order to obtain improved lighting eil'ects, to dash the obiect. to be photographed irom several directions at one and the same time. This, oi course, requires a plurality of flash-lamps. when it'is attempted to connect two or more such saseou discharze'devices-in .charge device is the "thQEIMIS-MMB. devi chargethrough only one at parallel to the condenser, that the condenser will disthem, the other or however. it1isliound others'remaining inert.

R118 accordingly an object o! the present invention to provide for dischargin the condenser simultaneously through a plurality oi discharge devices connectedin parallel to the condenser.

As study has disclosed that the reason tor the failure or the condenser'to discharge through more. MAIN parallelly connectedgaseous-disrelativelylow resistance oi iurther obiect iswto provide an electric "system or the abovedescribed character in which the paralleiiy connected gaseous-discharge devices have resistances suflciently high to enable the voltage from the charged condenser to become stored up in each discharge circuit long enough to enable it to operate also on the other dischar e circuits. when the condenser discharges through one of the gaseous-discharge devices, therefore, it will discharge also through the other gaseous-discharge devices. It is iound that gaseous-discharge devices having positive voltage-current characteristic curves have guiiiciently high resistance tor the purp in hand.

with these ends in view, a ieature of the invention resides in connecting a single condenser through a single impedance to a source of directcurrent energy to charge the condenser from the source, and connecting the condenser to a plurality oi discharge devices oi the above-described character, so as to eil'ect discharge oi the condenser simultaneously through the discharge devices. The discharge circuits are thus connected in parallel to the same single coudenser, without any separating impedances.

Other and further objects will be explained hereinafter and will be particularly pointed out in the" appended claims.

The invention will now be described in connection with the accompanying drawing, in which Fig. l is a longitudinal section of a preferred gaseous-discharge device a plurality of which may be connected in parallel across a discharge condenser in accordance with the present invention; Fig. 2 is a transverse section taken upon the line 2-4 of Fig. 1, looking in the direction of the arrows; Fig. 3 is a voltage-current characteristic curve of the gaseous-discharge device illustrated in Figs. 1 and 2; and Fig. 4 is a diagrammatic view oi circuits and apparatus embodying the present invention.

The lower portion of the curve of Fig. 3 from the point B to the point C represents a positive voltage-current characteristic, such as may be obtained in a cathode-ray oscillograph with a gaseous-discharge device it such as shown in Figs. 1 and 2. The axis of abscissae represents current, I, and the axis 0! ordinates. voltage, E. Initially, at zero current, the voltage across the anode 1 and the cathode 9 of the gaseous-discharge flash-lamp device I! may be about 2000 volts, as represented by the ordinate oi the point A. When the hereinafter-described trip circuit is energized to eflect a discharge of a condenser ii through the gaseo -discharge device it, between the cathode I and the anode I. the voltampere characteristic progresses very rapidly along the upper portion of the curve 01 Fig. 3, from the point A to the point B, until the current, at the point B, attains a maximum value of about 500 amperes. Thereafter the current through the tube it drops, as indicated by the lower portion oi. the curve of Fig. 3, from the point B to the point C, until the current again drops to zero, as represented by the point C. At this time. the voltage, as shown by the ordinate oi the point C, in Fig. 3 is relatively small, compared to the voltage represented by the ordinate of the point A. Depending upon the tube II and circuit conditions, this final voltage. represented by the ordinate oi the point C, may even be negative. The upper portion or this characteristic, between the points A and B, is shown constituted of long dashes, and the lower part, between the points B and C, or short dashes. If these dashes, long and short, respectively. be regarded as representing time intervals of corresponding duration, the upper portion AB of the curve will be seen to be traversed in about onet'hird the time that the lower portion B0 of the curve is traversed. Usually, the time required for the traverse or the portion A to B the curve is less than one-tenth 01' that for the portion B to C.

The resistance of the device Il may be defined as the ratio oi the voltage across its cathode l and its anode 9 at the time when the current is of a maximum value. From the curve of Fig. 3. it appears that the voltage is about 1500 at the time, represented by the point B, when the current has its maximum value of about 500. The resistance of the device I8, therefore, is approximately 3 ohms.

The positive-resistance characteristic, from the point B to the point C, is such that sumcient voltage remains across the hereinafter-described circuit, at the Point B, so that other tubes I 9 and 20, etc., in parallel with the tube I8, will have suflicient voltage across them to become ionized, even if the first tube I8 should start a few microseconds before the others. If the tubes have short lengths, with large cross sections, at low gas pressure. the point B on their characteristic will be reached quickly, and it will have so low a value that parallel-connected tubes will not flash, even if ionized by the herein-described starter electrode ll. The minimum value of the voltage corresponding to the point B for parallel operation is found to be in the range of voltage from 200 to 500 volts.

Higher-resistance gaseous-discharge devices is are particularly useful for connecting into parallel with the condenser II, as hereinafter described. Lower-resistance gaseous-discharge devices, having characteristics the upper portions AB of which are steeper than illustrated in Fig. 3, cannot be employed in this way.

The gaseous-discharge device I8 may be oi the type disclosed in Letters Patent 2,277,698, granted March 31, 1942, to Kenneth J. Germeshausen, or an application of the said Germeshausen, Serial No. 418,403, filed November 8, 1941. It is shown disposed within an elongated, light-permeable glass-bulb protective Jacket or envelope 2B, which is shown mounted in a reflector 25. It may contain krypton, xenon or any other suitable gas. The glass bulb 28 is cemented to a flat insulating base plug 94, provided with three plug-in pin terminals 6, I2 and I4 for connecting the gaseousdischarge device I8 into circuit. Other gaseousdischarge devices may, of course, also be employed in accordance with the present invention.

The gaseous-discharge device i8 is shown helically coiled, and provided at one end 01 the helix with a return center leg at the end of which the cathode l is mounted, the anode 9 being disposed at the other end of the helix. The oathode I and the anode 9 are respectively connected to the pin terminals 6 and I2. One end of the before-mentioned starter electrode ll, shown as a high-voltage spark trigger-wire or trip-wire flashing electrode, is connected to the plug-in terminal I4, and at its other end is mounted over a plurality of the coils or turns of the helicaltube gaseous-discharge device I8.

One side of the condenser II is shown connected by conductors 8 and ll to the terminal pin I2. A grounded terminal I at the other side of the condenser is shown connected by conductors 21 and 82 to the terminal pin .6. The gaseous-discharge device III is thus connected across the condenser II.

The condenser II may be discharged, as hereinaiter more fully explained, by means of a triggering circuit comprising a normally ineflective,

because non-conducting, gaseous-discharge trigger tube I. The trigger tube I is shown connected to terminals I 8 and I 3 across an impedance II. illustrated as a. bleeder resistor. so as to be supplied with voltage therefrom. The bleeder resistor is connected in series with a bleeder resistor 82 across the condenser II, which thus, by supplying energy to the bleeder resistor II, constitutes the main power supp y for the tube I.

The tube I may, if desired, be of the coldcathode gaseous-discharge type illustrated and described in Letters Patent 2,185,189, 2,201,186 and 2,201,167, issued to Kenneth J. Germeshausen, on January 2, 1940, and May 21, 1940. It may comprise an evacuated glass envelope containing several electrodes, namely, a solid cathode 2, an anode or plate 5, and one or more grids, inner and outer grids being shown at I and 4, between th anode 5 and the cathode 2. As explained in the said Letters Patent, the source or the electrons is a bright cathode spot on the surface 01 the cathode 2. Part of the impedance BI is shown connected between the cathode 2 and the grid 4, and a further impedance (not shown) may, if desired, be connected between the oathode 2 and the grid 3.

A trigger-discharge circuit for a tripping condenser M is also connected to the terminals I3 and IS, in parallel with the tube I. One side of the condenser 4| is connected in this discharge circuit to the terminal I3. The other side of the condenser II is connected, by way of a conductor 9|, to the primary winding 14 of a tripping transformer 36 and, by way of conductors I2 and ll, to the terminal I5. The condenser 4| is thus connected in this discharge circuit in series with this primary winding 14. One side of the secondary winding 38 'or the transformer 38 is grounded to the terminal I5 by way 0! the conductors 32 and 21. The other side oi the secondary winding 38 is connected through the terminal I4 to the trip electrode ll. A return path is afforded by capacity coupling of the trip-wire electrode H to the flash-lamp ID. The discharge circuit of the condenser 4| thus contains the gaseous-discharge device IB and the secondary winding 38, which operates as an induction coil.

The condenser I I may be supplied with directcurrent energy from any desired source, such as a battery. It a suitable source of alternating current, such as the ordinary volt, BO-cycle house mains is available, however, the condenser Il may be connected thereto by plugging at H. The plug II is connected by input wires II to a jack I16, which is connected by conductors Ill and III to the primary winding 15 ore, transformer 45. The secondary winding 48 of the transformer 45 is connected to the condenser lI through a rectifier [2. The rectifier I2 may also be supplied with energy from this alternatingcurrent source. To this end, its cathode 19 may be connected, by conductors III and I23, in circuit with a winding 83 that may constitute a further secondary winding for the primary winding 15 of the transformer 45. a

A charging impedance, which may be constituted oi resistance, or inductance, or both, may

be connected in circuit between the condenser i I and the secondary winding 49. This is not illustrated, because not needed it the secondary winding 49 has a high impedance. for it may then perform, also, the current-limiting function 0! a separate charging resistor or other impedance.

In this manner not only the condenser II, but,

. cue-discharge device, in any desired way.

accuses aiso,thecondenserllbe'comeschargediromthe same direct-current source ll, ll.

'I'hetubeimaybetriggeredtoinitiate the discharge of thecondenlcr ll throughtheswz;

as means of a manually controlled switch. but an automatically operated switch Ii is shown connected across the anode or plate 5 and the grid 4 ofthetube I. 'lhcconnectionsmaybetraced ll andaleakresisto OLinpuallcLbywayof a conductor ll, through the automatically operating switch ll and, by way or a conductor II, to the anode I.

At any time after the direct-current source It, I 2 charges the condenser I l to it maximum value, upon the closing of the automatically operating switch II, the potential of the grid I will become raised, until the break-down voltage between the grid 4 and the cathode I. or the grid and the grid I, is exceeded. The normally inefl'ective trigger tube thereupon becomes eflective by being rendered conducting. Current then flows through the trigger tube I, causing the condenser M, which had become charged from the directcurrent source I, 12 simultaneously with the charging of the condenser l Lto discharge through its before-described trigger-condenser-discharge circuit comprising the primary winding 'llof the transformer 80. A resulting voltage-surge pulse of the secondary winding II of the transformer 3! becomes thus impressed upon the trigger electrode ll of the gaseous-discharge tube It. This causes the gas in the gaseous-discharge tube II to ionlze. producing a conducting mth through the device II, and permitting the condenser II to discharge therethrough. The resulting highvoltage triggering spark through the flash-lamp II will yield a very brilliant exposure hash of extremely short duration. As the time taken for the trigger tube i to trip the gaseous-discharge device It, between the closing of the switch SI and the flash of light from the device i8, is very brief, it is possible to produce this very brilliant flash of light for a very brief period 0! time. when the condenser ii is fully discharged, the gaseousdlscharge device ll extinguishes, and the cycle is ready for repetition.

The duration of the iiash is nearly exponential in nature, and has a time constant approximately equal to the product sistance of the tube ll, ii only one tube is used. If two similar flash tubes are used in parallel, the eflective resistance is approximately half of that of one lamp II. The resulting flash is half as long, but also contains hall as much light from each tube. The total light is the same for both one or two tubes. If the lamps l8, il, etc.. have diflerent resistances, the output and the duration of each are calculated approximately as though the lamps were resistors, using Ohms law. The above methods are applicable only when the energy per flash is enough thermally to ionize the gas in the lamps. For the example shown, the tube may have dimensions as follows:

7 is about or 10 microiarads.

According to the present invention a plurality of the capacity II by the reof which are shown at II and 20, may be connected across the condenser il in parallel with the gaseous-discharge de ice it. The pin terminals I! of the gaseous-discharge devices It and a are shown connected to one side of the condenser ii, in parallel with the corresponding pin terminal I! of the gaseous-discharge device ll, by conductors I and It. The pin terminal ll of the gaseous-discharge device it is shown connected to the 20 by'a conductor 44, and the pin terminal I! of the device 2| by a conductor II.

The terminals. oi the gaseous-discharge devices II and Il may, similarly. be connected, in parallel with the corresponding terminal I or the gaseous-,discharge'device II, to the grounded terminal ll at the other side of the condenser II. The connections may be traced from the grounded terminal II, by way of conductors 21 and II, to a conductor ll leading to the pin terminal I of the gaseous-discharge device it and a conductor I! leading to the pin terminal I of the gaseousdlscharge device II.

Separate, tripping condensers 4! and ll, corresponding to the condenser 4i. and separate trippins transformers It and 00, corresponding to the transformer I, are provided for the gaseous-discharge devices it and 20. The condenser 42 and the primary winding 41 of the transformer 46, and the condenser 48 and the primary winding 54 of the transformer I, are respectively series-connected in tripping condenser-discharge circuits, in parallel with the condenser II and the primary winding it of the transformer 38. The tripping condenser-discharge circuit for the gaseous-discharge device ll may be traced from the terminal it. through the condenser 42, by way of a con doctor 02, through the primary winding 41 of the transformer I, and by way of conductors l0, l0 and 21, to the grounded terminal I. The tripping condenser-discharge circuit for the gaseousdischarge device 20 may be traced from the terminal it, through the condenser II, by way of a conductor 83, through the primary winding 54 of the transformer 50, and by way of conductors 62, it and 11. to the terminal II.

The secondary winding ll 0! the transformer It is connected to the pin terminal ll of the gaseous-discharge device I! and the grounded terminal ll by way of the conductors 40. ii and 21, and the secondary winding II of the transformer St is connected to the pin terminal ll of the gaseous-discharge device 20 and the grounded terminal I! by way of conductors It, It and II, in a manner similar to the connection of the secondary winding It of the transformer It to the terminal ll of the gaseous-discharge device it and the grounded terminal II.

By reason oi the fact that the resistances of the gaseous-discharge devices II, II and 20 are sumciently high, as depicted by the characteristic curve of Fig. 3, a discharge oi the condenser I! will take place through not one only of the gasenus-discharge devices II. I! and 20, but simultaneously through all three of them. The total amount of energy discharged by the condenser ii into these three gaseous-discharge devices II, II and 20 is, of course, approximately the same as that which would be discharged through a single gaseous-discharge device. if no more than a single gaseous-discharge device were connected to the condenser ii. The energy discharged by the condenser II is the same, whether dissipated in one gaseous-discharge device or many.

It is frequently desirable. however, as beiore of additional gaseous-discharge lamp devices. two stated, to discharge the energy of the condenser Ii simultaneously through a plurality of gaseousdischarge devices it, I! and 20. In flash photography, ior example, it is frequently desired to employ a number 01' flash-lamps ll, II and II disposedindiirerentregionsottheroomsoasto focus light upon the object to be photographed from diilerent directions. According to the present invention this may be eil'ected by connecting in parallel to the condenser ll, as illustrated, a plurality of flash-lamps it. it and II, each having a positive voltage-current characteristic, as illustrated in Fig. 3. and providing only a single current-limiting impedance for the condenser l I, which may be embodied in the secondary winding as. or which may be constituted of a separate charging resistor or other impedance (not shown) connected between the secondary winding II and the condenser ii. If the voltage across the condenser supplied by the secondary winding is and the rectifier 12 is, say, 2000 volts, the maximum current supplied by the condenser ll may be in the neighborhood of 500 amperes, as illustrated in Fig. 3, and the resistors Ii and I! may be so proportioned that a desired voltage of, say, 300 volts shall appear across the terminals l8 and It 01 the resistor II.

Modifications will occur to persons skilled in the art and all such are considered to fall within the scope and spirit of the invention.

What is claimed is:

1. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices, means for connecting the gaseous-discharge devices in parallel to the condenser, a plurality of triggering circuits, one connected to each of the gaseens-discharge devices, and means for simultaneously triggering the triggering circuits to eflect a discharge of the condenser simultaneously through the gaseous-discharge devices.

2. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of discharge circuits each having a gaseous-discharge device, means for connecting the discharge circuits in parallel to the condenser, a plurality of triggering circuits, one connected to each or the gaseous-discharge devices, a turther discharge device, and means controlled by the further discharge device for controlling the triggering circuits to eiiect a discharge of the condenser through the gaseous-discharge devices, the gaseous-discharge devices having resistances suillciently high so that when the condenser dischargesthrough one or the gaseo -discharge devices it shall discharge simultaneously through the other gaseous-discharge device.

3. An electric system having, in combination, a condenser, a plurality of discharge circuits each having a gaseous-discharge device having a positive voltagecurrent characteristic curve, means for connecting the discharge circuits in parallel to the condenser, and a breaker circuit iecting a discharge of the condenser through the gaseous-discharge devices, the breaker circuit having a breaker contact member and a condenser connected in series therewith.

4. An electric system having. in combination, two terminals that may be connected to a source oi energy. a condenser that may be connected to the two terminals so as to become charged iron: the source. a plurality oi discharge circuits each connected to the terminals and each having a gaseous-discharge device provided with a cathode and an anode respectively connected to the two terminals and a control electrode, a trigger circuit connected between the cathode and the control electrode of each discharge device. and means for simultaneously triggering the trigger circuits to eirect simultaneous discharge or the condenser into the discharge circuits.

5. An electric system having, in combination, a condenser, animpcdance, means for connecting the condenser to a source of direct-current energy through the mpedance to charge the condenser, a plurality of discharge circuits each having a gaseous-discharge device, means ior connecting the discharge circuits in parallel to the condenser without substantial separating impedance between the parailelly connected discharge circuits and the condenser, and means ior enacting a discharge of the condenser simultaneously into the discharge circuits.

6. An electric system having, in combination, a condenser, an impedance, mean for connecting the condenser to a source oi direct-current energy through the impedance to charge the condenser, a pluarlity oi gaseous-discharge devices, means for connecting the gaseous-discharge devices to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and means for eflecting a discharge of the condenser through the gaseousdischarge devices, the impedances or the gaseousdischarge devices being sufliciently high so that when the condenser discharges through one of the gaseous-discharge devices it shall discharge simultaneously through the other gaseous-discharge device or devices.

'7. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source 0! direct-current energy through the impedance to chargethe condenser, a plurality oi gaseous-discharge devices,

, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, triggering means, and means for triggering the triggering means to effect a discharge 0! the condenser simultaneously through the gaseous-discharge devices.

8. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and means for effecting a discharge of the condenser through the gaseous-discharge devices, the impedances of the gaseous-discharge devices being sumciently high so that when the condenser discharges through one of the gaseous-discharge devices it shall discharge simultaneously through the other gaseous-discharge device or devices.

' 9. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each having a positive voltage-current characteristic curve, and means for connecting the gaseousdischarge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and means for eflectlng a discharge of the condenser through the gaseous discharge devices.

10. An electric system having, in combination, a condenser, means ior charging the condenser, a plurality of discharge circuits each having a gaseous-discharge device, a plurality of tripping transformers, one for each discharge device, means for connecting each transformer to the corresponding discharge device, and means for simultaneously tripping the transformers to discharge the condenser into the discharge circuits.

11. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of discharge circuits each having a gaseous-discharge device, means for connecting the discharge circuits in parallel to the condenser, a plurality of tripping condensers, one for each discharge-device, means for connecting each tripping condenser to the corresponding discharge device, and means for simultaneously tripping the tripping condensers to eflect a discharge of the first-named condenser simultaneously into the discharge circuits.

12. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each provided with a normally unenergized starting electrode, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and means for simultaneously energizing the starting electrodes to discharge the condenser simultaneously through the gaseousdischarge devices.

13. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices, means for connecting the gaseous-discharge devices di-' rectly in parallel to the condenser with'out substantial separating impedance between the gaseens-discharge devices and the condenser, a tripping transiormer connected with each discharge device, a tripping condenser connected with each transformer, and means for simultaneously triping the tripping condensers to trip the tripping transformers to eifect a discharge of the flrst- .iamed condenser through the gaseous-discharge devices, the gaseous-discharge devices having impedances suniciently high so that when the first-named condenser discharges through one of the gaseous-discharge devices it shall discharge simultaneously through the other gaseens-discharge device or devices.

14. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each having a positive voltage-current characteristic curve, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and a breaker circuit for eifecting a discharge of the condenser through the gaseousdischarse devices.

15. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source of directcurrent ener y through the impedance to charge the condenser, a, plurality of discharge circuits, means for connecting the discharge circuits in parallel to the condenser without substantial separating impedance between the paralleily connected dis-- charge circuits and the condenser to eflect a discharge of the condenser simultaneously into the discharge circuits, and a contact member for controlling the discharge of the condenser.

16. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source of direct-current energy through the impedance to charge the condenser, a plurality of gaseous-discharge devices, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseens-discharge devices and the condenser, a plurality or tripping transformers, one for each gaseous-discharge device, means for connecting each transformer to the corresponding discharge devices, and means for simultaneously trlllpm the transformers to eflect a discharge of the condenser through the gaseous-discharge devices, the impedances of the gaseous-discharge devices being sufficiently high so that when the condenser discharges through one of the gaseous-discharge devices it shall discharge simultaneously through the other gaseous-discharge device or devices.

17. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each provided with a cathode, an anode and a control electrode, means ior connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, a plurality of transformers, one let each gaseous-discharge device, and each having a primary winding and a secondary winding connected between the cathode and the control electrode of the corresponding gaseous-discharge device, and means for simultaneously energizing the primary windings to cause the secondary windings to effect control over the control electrodes, thereby to eflect simultaneous discharge of the condenser through the gaseousdischarge devices.

18. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each provided with a cathode, an anode and a starting electrode, means for connecting the gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, a tripping condenser connected to each starting electrode, and means for simultaneously tripping the trippin condensers to energize the starting electrodes, thereby to effect simultaneous discharge of the first-named condenser through the gaseous-discharge devices.

19. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source of direct-current energy through the impedance to charge the condenser, a plurality of gaseous-discharge devices each having a positive voltage-current characteristic curve, means for connecting the gasenus-discharge devices in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, and a breaker circuit for eflecting a discharge or the condenser simultaneously through the gaseous-discharge devices, the breaker circuit having a breaker contact member and a condenser connected in series therewith.

20. An electric system having, in combination, a condenser. an impedance, means for connecting the condenser to a source of direct-current energy through the impedance to charge the condenser, a plurality of gaseous-discharge devices each provided with a cathode, an anode and a control electrode, means for connecting th gaseous-discharge devices directly in parallel to the condenser without substantial separating impedance between the gaseous-discharge devices and the condenser, a triggering circuit connected between the cathode and the control electrode of each discharge device, and means for simultaneously triggering the triggering circuits to discharge the condenser into the discharge circuits, the impedances of the gaseousdischarge devices being sumciently high so that when the condenser discharges through one of the gaseous-discharge devices it shall discharge simultaneously through the other gaseous-discharge device or devices.

21. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source of direct-current energy through the impedance to charge the condenser, a plurality of gaseous-discharge devices each having a positive voltage-current characteristic curve and each having a cathode, an anode and a control electrode, means ior connecting the discharge circuits in parallel to the condenser, and means controlled by the control electrodes for eilecting a discharge of the condenser simultaneously through the gaseous-discharge devices.

22. An electric system having, in combination, a condenser, an impedance, means for connecting the condenser to a source of direct-current energy through the impedance to charge the condenser, a plurality of discharge circuits each having a gaseous-discharge device capable of carrying large currents and having a positive voltage-current characteristic curve, means for connecting the discharge circuits in parallel to the condenser, and means for eiiecting a discharge 0! the condenser through the gaseous-discharge devices.

23. An electric system having, in combination, a condenser, means for charging the condenser, a plurality oi gaseous-discharge devices, means for connecting the gaseous-discharge devices in parallel to the condenser, triggering means, and means for triggering the triggering means to eii'ect a discharge oi the condenser simultaneously through the gaseous-discharge devices.

24. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices. means for connecting the gaseous-discharge devices in parallel to the condenser, triggering means, and means for triggering the triggering means to eflect a, discharge of the condenser through the gaseous-discharge devices, the impedances of the gaseous-discharge devices being sufliciently high so that when the condenser discharges through one oi the 8aseous-discharge devices it shall discharge simultaneously through the other gaseens-discharge device or devices.

25. An electric system having, in combination, a condenser, means for charging the condenser, a plurality of gaseous-discharge devices each having a positive voltage-current characteristic curve, means for connecting the gaseous-discharge devices in parallel to the condenser, triggering means, and means for triggering the triggering means to effect a discharge of the condenser simultaneously through the gaseous-discharge devices.

HAROLD E. EDGERTON. 

